Tag Archives: RWIS

Utah DOT’s Weather Operations Program Celebrates its 15th Year

Utah DOT’s Weather Operations Program Celebrates its 15th Year


October 2016

The UDOT Weather Operations Program is celebrating its 15th year of managing weather events throughout the state of Utah. Beginning officially with the 2002 Winter Olympics, the Weather Operations program has reached many milestones over the years. Nearly 20 years ago, UDOT’s first contract meteorologist began with forecasts for a small section of the state. Today, UDOT employs a full time UDOT Weather Operations Manager, 8-12 meteorologists and a UDOT weather research analyst.


Figure 1A UDOT RWIS deployment.

So, how has the program grown and changed over time?

UDOT meteorologists handle over 5,000 phone calls in a typical winter season. There is a significant amount of coordination with the National Weather Service and UDOT plow crews. Ahead of any major weather events, including winter storms, wind events and rain/floods, UDOT’s Weather Operations group will host a weather briefing, sharing critical and timely information. UDOT signals, traveler information, operations, Ports of Entry, Utah Highway Patrol, communications and other teams are all participants.

The UDOT Citizen Reporter program smartphone apps for iOS and Google Play were launched in October 2013 to allow motorists to report road and weather conditions to UDOT. The UDOT app was the first of its kind in the country! UDOT has received thousands of reports from citizens since the program launched and reminds all drivers to never use apps while driving.


Figure 2 The UDOT Citizen Reporter app is a free download for iPhone and Droid.


Figure 3 Sign up to be a UDOT Citizen Reporter.

A new feature to the UDOT Traffic app and website is the Automatic Vehicle Location (AVL) of all UDOT plows during storms. A citizen can get, at a glance, an understanding of where all UDOT plows are currently working. This enhancement also allows UDOT to better track plow movements for possible equipment and material savings. Overall, this enhancement has been very well received by the public.



Figure 4UDOT plows at work during a winter storm.

UDOT launched a Winter Road Weather Index (WRWI) project a few years ago to monitor snow and ice removal. The next generation of the WRWI is here… in the form of winter weather performance metrics. UDOT’s Snow and Ice performance metrics dashboard has real-time statistics that are utilized by UDOT maintenance crews to determine how effective they were at maintaining good road conditions during a storm. Several metrics go into creating the measure, including the intensity of the storm, length of time the storm is ongoing, resources allocated to the maintenance shed covering the geographic area and field instrumentation on the RWIS units. The resulting information is utilized to measure storm performance, identify best practices and possibly re-allocate resources to better cover areas in need.


Figure 5UDOT’s Snow and Ice Performance Measure uses green, yellow and red data points to assess how maintenance crews responded to the storm.

UDOT is fortunate to have an incredible crew of plow drivers who are very dedicated to their jobs and to Keeping Utah Moving. But there’s always room for improvement and sometimes opportunities for efficiency and resource allocation. In order to track performance and possibilities for improvement, the snow and ice performance metric takes into consideration several baseline data points including snow fall rate, time of day and shed resources.


Figure 6The UDOT Snow and Ice Performance measure graphic is available for each storm, allowing management to view an assessment and determine of additional resources are needed.

The graphic colors represented here show that UDOT’s crews managed the storm well but have some areas for improvement. The green data points show that when all factors are considered, the plow crews are exceeding expectations and are doing a great job keeping up with the storm and keeping the road well maintained. The yellow data points show that crews are performing within current capabilities for equipment and manpower. The red data points are highlighting areas for improvement where crews are not performing up to UDOT’s standards. Because the data comes to UDOT in real-time, a shed foreman has the ability to review the information at the end of the storm, end of the month or end of the season!

Under the red, yellow and green data point graph, the plow icon shows the movement of plows over the course of the storm.


Figure 7The Snow and Ice Performance metric includes details about the storm, including pavement temperature, storm intensity and precipitation type.


The archived snow and ice removal performance metric data includes atmospheric conditions, air temperature, pavement temperature, precipitation type and other meteorological factors that can help to determine the intensity


Figure 8UDOT Traffic camera screenshots are archived with each storm’s metrics to provide a visual description of the storm.

of the storm. UDOT Traffic camera screenshots are also included to give a data user a visual of the road during the storm. All of this information comes together to give shed crews and UDOT leadership an idea of how resources are being utilized and where there are areas for improvement.

UDOT is ready for the winter season and we hope you are, too. Now would be a good time to check the condition of your tires and ensure you have an emergency kit in your trunk. Please remember: always buckle up and never drive distracted. Check the UDOT Traffic app or website before every trip.



Optimizing Mobility

As we continually look for ways to improve our processes with the ultimate goal of keeping drivers moving on Utah’s roads, UDOT has deployed a number of technological tools that align with our strategic direction to preserve infrastructure, optimize mobility, reach our goal of zero fatalities, and strengthen the economy. I wanted to particularly emphasize what we are currently doing as a department in regards to our goal of optimizing mobility, which, in our day and age, no longer only applies to people’s ability to keep moving but also to their ability to do things as they are moving (but not driving), via phone apps.

These UDOT phone apps are allowing citizens to perform a variety of tasks, like reporting road conditions directly to operators at the Traffic Operations Center (TOC), or finding out what kind of delays to expect due to construction projects, and receiving severe weather event warnings. In addition to this ever evolving field of mobile technology, we continue to rely on innovative projects based on traffic models and engineering to not only improve mobility, but also safety, which in turn helps us achieve our goal of Zero Fatalities. Last year, Region Two completed several projects that illustrate exactly how we continue to optimize mobility through road and signal technologies.


UDOT Traffic

Screen shot of UDOT Traffic app
UDOT Traffic is the department’s portal for statewide traffic information and can be accessed through the UDOT Traffic website or via mobile application for iOS or Android devices. Citizens can use the site to view real-time traffic conditions, construction and emergency alerts, road weather forecasts, and current lane and ramp closures. New to the UDOT Traffic app is a map layer that displays designated bike routes across the state, and state roads with shoulders wider than four feet. The map also displays routes that are restricted to bicycles such as I-15 in the Salt Lake Valley.

UDOT continually upgrades the UDOT Traffic portal to make it even more useful for drivers and the public. This year, the Lane Closure tool will be used for all projects on interstates as well as major highways including Bangerter Highway, Legacy Parkway, S.R. 201, and U.S. 40.

Future updates will improve integration between construction projects and the Lane Closure tool, and will allow contractors and department employees to make changes to UDOT Traffic information using mobile devices.

Citizen Reporter

Screen shots of the citizen reporting app
UDOT Citizen Reporter is a mobile application that enlists volunteers to report on current weather conditions for specific roads across Utah. This app is designed to provide both TOC operators and travelers with more accurate and timely road, weather and travel impact information and forecasts.

To participate as citizen reporters, members of the public are required to take a short course (either online or in person), complete a quiz, and then submit a sign-up form. Once those steps are completed, the volunteer receives a login and password, and can then download the app and begin submitting reports.

Citizen reporters are able to confirm weather data received through other sources (Road Weather Information Systems, meteorological forecasts, etc.) and can provide data for roadways where RWIS systems or other information sources may not be available.


Variable Speed Limit

Photo of Variable Speed Limit sign with a semi passing by on I-80 in Parley's Canyon

Variable Speed Limit sign on I-80 in Parley’s Canyon

In January 2014, 15 new variable speed limit (VSL) signs were activated along I-80 in Parleys Canyon. The new signs are controlled by the TOC to help maintain consistent traffic flows and assist drivers in adjusting speeds when necessary due to weather conditions.

The TOC monitors speed limits in the canyon. In the event of poor weather or low visibility, a traffic engineer reviews information, such as current road conditions, weather forecasts, snowfall rates, observed speeds, and reports from maintenance personnel. Based on this information, the engineer can make the decision to reduce the speed limit as needed. Speed limits typically range from 35 to 65 miles per hour depending on conditions.

The new VSL signs are the first of their kind in Utah. UDOT is also considering installing variable speed limit signs in other locations around the state, such as Provo Canyon and Sardine Canyon, based on the results of this project.

Bike Detection

Photo of open signal cabinet
Last year, Region Two and the TOC worked together to develop and install reliable bicycle detection at nine signalized intersections in Salt Lake City, along with new pavement markings to show bicyclists where to stop. Often, bicyclists stop at red lights, look to see if they feel it is safe to cross, and then proceed through the intersection without waiting for a green signal; these upgraded intersections help encourage cyclists to obey traffic signals.

Additionally, upgrading bicycle detection systems encourages cycling as a viable means of transportation. This helps improve air quality by reducing automobile emissions, and is an asset for local economic development since many companies have reported that Utah’s alternative transportation options (such as bicycling and mass transit) were a significant factor in their decision to come to the state.

Moving forward, the department is working with the bicycling community to identify additional high-priority intersections where this detection technology can be installed.

HAWK Crossings

Photo of HAWK signal with traffic flowing underneath


HAWK (High Intensity Activated CrosswalK) crossings have been installed in a number of locations in Region Two where arterial streets intersect with minor streets. These crossings include pavement markings, signs, and red and yellow lights on an arm over the roadway.

When a pedestrian pushes the button to activate the signal, the lights over the roadway begin flashing yellow, alerting drivers to slow down. A solid red light then activates, along with a “walk” sign for the pedestrian. Once the “walk” phase is complete, the light flashes red, indicating to drivers to treat the intersection as a stop sign – they may proceed if the crosswalk is clear. When the lights are off, drivers are not required to stop at the crosswalk.

These signals are in use at several locations throughout the Region where large numbers of pedestrians cross major roadways. UDOT continues to evaluate other locations for these signals and will install them as needed.

Behind the Scenes at UDOT – November 22, 2013 Wind Storm Response

Photo of UDOT personel receiving an update regarding the weather

UDOT Wind Event Weather Briefing

Weather events can have a huge impact on traffic and traveler delay. The UDOT Traffic Operations Center (TOC) handles routine day-to-day rush hour congestion and traffic signal timing smoothly after years of practice. But what about a large winter storm or wind event?

A significant amount of planning and consideration is needed to ensure that UDOT’s response to a storm is thorough and serving the needs of the public. For the high winds event that affected interstate and highway routes from Woods Cross to Centerville on Nov.21–22, 2013, TOC coordination started with a weather briefing. Weather briefings are generally held 24 to 48 hours before a storm to ensure that the incoming weather data is as accurate as possible. Many UDOT departments attend the weather briefings. The briefings are an essential tool to ensure that the UDOT response to an event

Photo of the portable RWIS stations next to I-15 in Centerville

UDOT Portable RWIS Station (Photo by Cody Opperman)

is coordinated and timely. “The weather briefing discussed what we anticipated, what steps they would take when certain thresholds were met, and a detailed schedule of who would be in charge throughout the event,” said Jason Davis, UDOT’s Director of Operations.

Photo of UDOT maintenance technician J.T. Dziatlik is foul weather gear

UDOT Maintenance Technician J.T. Dziatlik

Following the weather briefing, UDOT employees sprang into action. UDOT began strategically deploying equipment and personnel to assist with equipment malfunctions and outages due to the storm. The Traffic Operations Center had an event coordinator and meteorologist on staff around the clock for the duration of the event.

One of the most valuable pieces of equipment during a wind storm are the Road Weather Information System (RWIS) stations. A portable RWIS was deployed at the epicenter of the wind and communicated wind speeds and gusts back to the TOC. Over the course of the storm, the UDOT weather group posted dozens of Road Weather Alerts on the UDOT Traffic app, website and 511 phone line. The weather group was also in near-constant communication with UDOT’s region offices and maintenance sheds providing storm updates.

Whatever the Weather

During storms, driving conditions can cause travel delay, especially during the morning and evening commute.

When a storm hits the Wasatch Front, a twenty-minute commute can turn into an hour due to slick roads, start-and-stop traffic and low visibility. What if traffic could be managed more effectively to minimize the sluggish traffic speeds drivers experience during storms?

Recent technological advances in assessing weather and controlling signals have given traffic engineers better tools to keep traffic moving in stormy weather. On some corridors along the Wasatch Front, UDOT is taking a Weather Responsive Traffic Management approach that puts the tools to use.

WRTM uses sensors, traffic signal plans designed for storm conditions, and sophisticated traffic monitoring systems already in place to move traffic more efficiently during winter weather.

Traffic on Riverdale Road PhotoDuring winter months in 2013, an urban arterial in northern Utah served as testing area for WRTM. Riverdale Road intersects a busy shopping district and connects four Utah cities with Interstates 15 and 84. Over 47 thousand vehicles travel the corridor each day.

UDOT’s results in managing Riverdale Road traffic during winter storms were very good – for motorists, that is. Drivers experienced less stopped time at intersections compared to other storm days, and overall, traffic speeds were not significantly impacted by weather.

Here’s how the WRTM system worked on Riverdale Road:

  • Traffic engineers created signal timing plans for implementation before or during a storm. The plans accommodate travel speeds that are likely during storms so that signalized intersections along the corridor work together to make traffic flow more efficient.
  • A Road Weather Information System unit was installed in the corridor. The RWIS helped meteorologists and engineers anticipate upcoming storm severity to decide which signal timing plan to employ.

    RWIS on Riverdale Road Photo

    RWIS on Riverdale Road

  • Detection units were installed overhead along the roadway. The new equipment is better at detecting traffic movement during storms, and the equipment gave UDOT traffic speeds.
  • To monitor traffic during storms, UDOT used a Signal Performance Metrics System that lets signal operators assess and adjust traffic in real-time. After a storm, the system can be used to evaluate how the signal plans worked.

Winter 2013 ended up being a challenging year to test the WRTM system. During testing, the Salt Lake City and Ogden area experienced one of the worst winter storms in the past decade. Nevertheless, post-storm review showed an average or above average improvement in performance in traffic operations in over half of the weather events, including during the major storm.

Post-storm analysis also shows that cars maintained a high level of progression from intersection to intersection with platoons of cars arriving on green lights. When platoons of cars arrive at intersections on green lights, traffic flow throughout the corridor is more efficient.

Based on the success of the Riverdale Road WRTM performance, UDOT plans to expand the system to other corridors.

UDOT’s Road Weather Information System Network helps with safety

RWIS Network Map

UDOT RWIS network

Utah’s unique geography can be a challenge for traffic management and safety. Many of the critical highway routes in the state are in rural areas and can be prone to flooding, snow drifts, landslides, high winds or low visibility due to wild fire smoke. UDOT’s Road Weather Information System (RWIS) network currently has nearly 80 deployments throughout the state. An RWIS unit has several weather sensors that calculate wind speed, precipitation type, roadway temperature and more. Some RWIS have a traffic camera as well.

Utah has had an active winter and spring with several large storms, flooding and landslides. In June, UDOT deployed a portable RWIS unit near Monument Peak on SR-31. This site was adjacent to an area that was burned in a forest fire and was at risk for landslides. The portable RWIS can be relocated at a later date for other uses. The RWIS sends alerts to the UDOT Traffic Operations Center (TOC) meteorologists who can then contact UDOT crews and UDOT management working in a specific area and alert them to any danger of landslides or flooding. The alert information is also shared with the National Weather Service, the National Forest Service, the United States Geological Survey, Utah Highway Patrol and other agencies. UDOT contracts with Northwest Weathernet for meteorological services and RWIS installation.

Photo of portable RWIS station

Portable RWIS unit being deployed for use during the Rockport 5 Fire


Screen shot of RWIS alert

A rainfall alert from the portable RWIS


For more information about our use of RWIS also check out RWIS Update and Forecasting for Smarties.